Liquid crystal display apparatus and method of manufacturing the same

ABSTRACT

A method of manufacturing a liquid crystal display apparatus includes adhering an array substrate and a counter substrate to form a liquid crystal cell; injecting liquid crystal between the array substrate and the counter substrate; adhering an optical film having been cut away at one corner thereof in a triangular shape on the surface of the counter substrate: and mounting a back light to the liquid crystal cell by aligning a corner of the liquid crystal cell and a corner of the back light on the notched portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2013-142623, filed on Jul. 8,2013; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments of the present invention relate to a liquid crystal displayapparatus and a method of manufacturing the same.

BACKGROUND

A liquid crystal cell includes an array substrate and a countersubstrate adhered to each other and liquid crystal injectedtherebetween. Front surfaces of the array substrate and the countersubstrate each have an optical film such as a polarizing plate or aretardation film adhered thereto.

In recent smart phones or the like, frame narrowing that narrows anoutside portion of a display area is required for enlarging a displayarea with a limited liquid crystal cell size.

However, when adhering an optical film on a liquid crystal cell with anarrowed frame as described above, the position of adhesion is affectedby repeating accuracy of an adhering apparatus and outline accuracy ofthe optical film or a glass substrate. Therefore it is difficult toadhere the film always at the same position.

Therefore, as illustrated in FIG. 6, when a corner of an optical film 20protrudes from a corner of the counter substrate 14 as a result ofadhesion, the protruded corner of the optical film 20 is erroneouslyrecognized as the corner of the counter substrate 14 in a process ofmounting a back light to a liquid crystal cell. Therefore, the positionof the counter substrate cannot be determined, so that a problem theback light cannot be mounted on the liquid crystal cell accuratelyarises.

In view of such a problem described above, it is an object of thepresent invention to provide a liquid crystal display apparatus whichallows a liquid crystal cell and a back light to be mounted correctlyeven though the liquid crystal cell is subjected to frame narrowing anda method of manufacturing the same.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a state in which a back light is beingmounted on an array substrate according to an embodiment of the presentinvention;

FIG. 2 is a plan view illustrating a relationship between a countersubstrate and an optical film;

FIG. 3 is a perspective view of a state in which a liquid crystal celland a back light are mounted;

FIG. 4 is a vertical cross-sectional view of a liquid crystal displayapparatus;

FIG. 5 is an exploded perspective view of the back light; and

FIG. 6 is a drawing illustrating a relationship between the optical filmand the counter substrate of the related art in a state in which theoptical film is protruded.

DETAILED DESCRIPTION

According to embodiments, the embodiment provides a method ofmanufacturing a liquid crystal display apparatus including: forming aliquid crystal cell, in which a liquid crystal layer is held between anarray substrate and a counter substrate; adhering an optical film havinga notched portion formed by cutting at least one of corners away on afront surface of the array substrate or the counter substrate of theliquid crystal cell; aligning a corner of the liquid crystal cell and acorner of a back light at the notched portion of the optical film; andmounting the back light so as to overlap with the liquid crystal cell.

The embodiment of the present invention provides a liquid crystaldisplay apparatus including a liquid crystal cell having an arraysubstrate and a counter substrate adhered to each other by theintermediary of a liquid crystal layer and a back light, wherein atleast one of four corners of an optical film to be adhered to thecounter substrate is cut away to form a notched portion.

According to the embodiments of the invention, since the corner of theoptical film adhered to the counter substrate is cut away to form thenotched portion, even though the optical film is adhered to the liquidcrystal cell with a narrowed frame so as to protrude from the countersubstrate, the corner of the liquid crystal cell and the corner of theback light are exposed from the notched portion so that accuratealignment between the liquid crystal cell and the corner of the backlight is achieved.

A liquid crystal display apparatus 1 and a method of manufacturing thesame according to an embodiment of the invention will be described withreference to FIG. 1 to FIG. 5.

A structure of the liquid crystal display apparatus 1 will be describedwith reference to FIG. 4 and FIG. 5.

The liquid crystal display apparatus 1 includes a liquid crystal cell 2and a back light 3 combined with each other.

The liquid crystal cell 2 includes an array substrate 12 and a countersubstrate 14 adhered to each other with a sealing member 4 by theintermediary of a liquid crystal layer 16.

Gate lines and signal lines are formed on an upper surface of a glasssubstrate 9 of the array substrate 12 orthogonally to each other, andpixel portions each including a TFT (Thin Film Transistor) and a pixelelectrode are arranged at intersections thereof in a matrix pattern. Anoptical film 18 formed of a polarizing plate or a retardation film isadhered to a lower surface of the array substrate 12. The arraysubstrate 12 is formed to be larger than the counter substrate 14, and ashelf portion 5 for mounting a driver IC for driving the liquid crystalcell 2 is provided.

On a lower surface of the glass substrate 10 of the counter substrate14, a colored layer including resists colored in different colors (R, G,B), a black matrix, and a transparent electrode applied to an uppersurfaces of the colored layer and the black matrix are formed. Anoptical film 20 including the polarizing plate or the retardation filmis adhered to an upper surface of the counter substrate 14. A corner ofthe optical film 20 includes a notched portion 6 formed by cutting atriangle shape away therefrom. The size of the notched portion 6 is suchthat one side of the triangle cut away is 0.3 mm as illustrated in FIG.2, for example.

Opposing surfaces of the array substrate 12 and the counter substrate 14each include an alignment film formed thereon, and a liquid crystallayer 16 is formed between the array substrate 12 and the countersubstrate 14.

The back light 3 includes a light guide plate 24 stored in aframe-shaped frame 22 formed of synthetic resin, a diffusion sheet 26,and prism sheets 28 and 30 laminated on an upper surface of the lightguide plate 24, and a frame-shaped light-shielding double-side adhesivetape 32 for adhering the liquid crystal cell 2 is adhered to an uppersurface of the prism sheet 30. A reflection sheet 34 is arranged on alower surface of the light guide plate 24. A plurality of LEDs 36, whichfunction as a light source, are arrayed between the frame 22 and thelight guide plate 24, and the LEDs 36 and the LED flexible substrate 38are fixed to the frame 22 with a fixing tape 40.

Subsequently, a method of manufacturing the liquid crystal displayapparatus 1 will be described in sequence.

First of all, a large mother substrate (hereinafter, referred to as a“mother array substrate”) for forming pieces of array substrates 12 isprepared. In order to do so, a film is formed on the front surface ofthe glass substrate, which serves as the mother array substrate. In thiscase, a metal film is formed by Spattering Method, and an insulatingfilm is formed by CVD method. Both are formed by adhering a metal filmor an insulating film on a glass substrate by charging gas into a vacuumchamber to cause a physical or chemical reaction.

Subsequently, a resist is applied on the glass substrate having themetal film or the insulating film formed thereon to form a resist layer.

Subsequently, an exposure apparatus is used to expose the glasssubstrate on which a resist layer is applied to perform development. Inother words, a mask on which the pattern is drawn is used to print thepattern on the resist layer.

Subsequently, the resist layer on which the pattern is printed iscovered with a mask, wet etching or dry etching is performed thereon,and unnecessary resist layer, the metal film, and the insulating filmother than the pattern are removed.

Subsequently, the unnecessary resist layer remaining on the patternedmetal film or insulating film is separated from the glass substrate toleave a required film only.

As regards the above-described processes, a single metal film orinsulating film is formed from a single mask. Therefore, these processesare performed repeatedly by a plurality of times to form wiring for gatelines, the insulating film, wiring for the signal lines, insulatingfilm, the TFTs, and the pixel electrodes.

Subsequently, the counter substrate 14 is formed by pattern formation inthe same manner as the process of manufacturing the array substrate 12by forming a black matrix, colored layer of RGB, and a transparentelectrode on a glass substrate, which becomes a large mother substratefor forming pieces of the counter substrates 14 (hereinafter, referredto as “mother counter substrate”).

Subsequently, the alignment film of the mother array substrate and thealignment film of the mother counter substrate 140 are applied by rollertransfer. The alignment film is provided for aligning the orientation ofliquid crystal molecules.

Subsequently, a rubbing process is performed on the alignment film onthe mother array substrate and the alignment film on the mother countersubstrate, respectively. For example, a drum is wrapped with a cloth andthe surface of the alignment film is mechanically rubbed, so that theliquid crystal molecules align in the rubbing direction.

Subsequently, the sealing members 4 are formed in a frame shape alongouter peripheral areas of the pieces of the counter substrates 14 on themother counter substrate.

Subsequently, the mother array substrate and the mother countersubstrate are adhered with the sealing members 4.

Subsequently, liquid crystal is injected into a space between the motherarray substrate and the mother counter substrate adhered to each otherby, for example, dropping the liquid crystal, so that the liquid crystallayer 16 is formed.

Subsequently, the sealing members 4 that adhere the mother arraysubstrate and the mother counter substrate to each other are irradiatedwith a UV light beam and cured.

Subsequently, after the sealing members 4 have cured, the adhered mothersubstrates are divided into pieces of the liquid crystal cells 2 byperforming a scribe and break process, whereby individual liquid crystalcells 2 are formed.

Subsequently, the optical films 18 and 20 are adhered to the surfaces ofthe array substrate 12 and the counter substrate 14 of the liquidcrystal cell 2. In such a case, as described above, the corner of theoptical film 20 to be adhered to the counter substrate 14 is cut away ina triangle shape and hence includes the notched portion 6.

Subsequently, the back light 3 is aligned with the liquid crystal cell 2as illustrated in FIG. 1, and then mounted in an overlapped manner asillustrated in FIG. 3. The back light 3 is fixed to the lower surface ofthe array substrate 12 of the liquid crystal cell 2 by a light-shieldingdouble-side adhesive tape 32. In this case, a corner of the liquidcrystal cell 2 on the side opposite from the shelf portion 5 and acorner of the back light 3 need to be matched. Therefore, as illustratedin FIG. 1, the corner of the liquid crystal cell 2 and the corner of theback light 3 are shot by a camera 7 from an upper surface of the liquidcrystal cell 2, and the back light 3 is shifted so as to match theposition of the corner of the liquid crystal cell 2. In this case, sincethe corner of the optical film 20 has the notched portion 6 cut away inthe triangular shape, even though the optical film 20 is protrudedoutward from the counter substrate 14, the positions of the corner ofthe liquid crystal cell 2 and the position of the corner of the backlight 3 may be confirmed through the position of the notched portion 6,so that accurate alignment is achieved. In particular, the optical film20 in these days often protrudes from the counter substrate 14 due tothe frame narrowing of the liquid crystal cell 2. Even in such a case,the corner of the counter substrate 14 and the corner of the back light3 can be recognized from the notched portion 6 accurately by the camera7.

Subsequently, a driver IC, which is not illustrated, is mounted on theshelf portion 5 of the liquid crystal cell 2 on which the back light 3is mounted via the flexible substrate, whereby the liquid crystaldisplay apparatus 1 is completed.

According to the embodiment, the corner of the counter substrate 14 isprevented from being covered with the optical film 20 by providing thenotched portion 6 at the corner of the optical film 20, so thatalignment between the corner of the liquid crystal cell 2 and the cornerof the back light 3 is achieved accurately. Therefore, when the liquidcrystal cell 2 and the back light 3 are combined, light leakage and thelike does not occur.

In the embodiment described above, only one of the corners of therectangular optical film 20 is cut away. However, the notched portion 6may be provided at corners opposing each other or adjacent corners toperform alignment at a plurality of positions in order to achievefurther accurate alignment.

As regards the shape of the notched portion 6, the mode of the triangleshape has been exemplified in the embodiment. However, what is essentialis that the corner of the liquid crystal cell 2 can be inspected throughthe notched portion 6, and hence the shape is not limited thereto as amatter of course. For example, by forming holes through the optical filmat positions corresponding to four corners of each optical film beforebeing cut out into pieces with a round hole punch or the like, the shapeof the notched portion at the corners when the optical film is cut outinto pieces becomes a fan shape. A rectangular shape is also applicable.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A method of manufacturing a liquid crystaldisplay apparatus comprising: forming a liquid crystal cell, in which aliquid crystal layer is held between an array substrate and a countersubstrate; adhering an optical film having a notched, portion formed bycutting at least one of corners away on a front surface of the arraysubstrate or the counter substrate of the liquid crystal cell; aligninga corner of the liquid crystal cell and a corner of a back light at thenotched portion of the optical film; and mounting the back light so asto overlap with the liquid crystal cell.
 2. The method of manufacturinga liquid crystal display apparatus according to claim 1, whereinaligning the corner of the liquid crystal cell and the corner of theback light is performed by observing the corners through the notchedportion from above the counter substrate.
 3. The method of manufacturinga liquid crystal display apparatus according to claim 1, wherein theoptical film is a polarizing plate or a retardation film.
 4. A liquidcrystal display apparatus comprising: a liquid crystal cell formed byadhering an array substrate and a counter substrate via a liquid crystallayer; and a back light, wherein at least one of four corners of anoptical film to be adhered to the array substrate or the countersubstrate is cut away to form a notched portion, an area of the opticalfilm is larger than the array substrate or the counter substrate atplaces except at the notched portion.
 5. The liquid crystal displayapparatus according to claim 4, wherein the optical film is a polarizingplate or a retardation film.
 6. The liquid crystal display apparatusaccording to claim 4, wherein a side of the notched portion is formed tobe inclined to a side of the optical film, and the corners of the liquidcrystal cell and the backlight are exposed in the notched portion. 7.The liquid crystal display apparatus according to claim 4, wherein, atthe notched portion, a fringe of the optical film runs in a directioninclined to directions of fringes of the optical film in other parts sothat a corner portion of the back light is observable through the arrayand counter substrates; which are transparent, when a frame covering anon-viewing fringe area of the liquid crystal cell is detached.
 8. Amethod of manufacturing a liquid crystal display apparatus comprising:forming a liquid crystal cell, in which a liquid crystal layer is heldbetween an array substrate and a counter substrate; adhering an opticalfilm having a notched portion formed by cutting at least one of cornersaway on a front surface of the array substrate or the counter substrateof the liquid crystal cell; aligning the liquid crystal cell and a backlight by observing corners of the liquid crystal cell and the back lightthrough the notched portion of the optical film; and mounting the backlight to overlap with the liquid crystal cell.
 9. A liquid crystaldisplay apparatus comprising: a liquid crystal cell formed by adheringan array substrate and a counter substrate via a liquid crystal layer;and a back light; wherein at least one of four corners of an opticalfilm to be adhered to the array substrate or the counter substrate iscut away to form a notched portion, dimensions of the optical film arelarger than corresponding dimensions of the array substrate or thecounter substrate so that fringes of the optical film outwardly protrudefrom fringes of the array substrate or the counter substrate at least invicinity of, and except at, the notched portion.